OB7 Offers Security, Seven Degrees of Cobot Freedom

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Collaborative robot arms are a relatively small but rapidly growing part of industrial automation, thanks to their promised benefits safety and flexibility. However, not all cobots are created equal. Productive Robotics Inc. has taken a different approach from other collaborative robot makers with its seven-axis OB7.

Zac Bogart, president of Productive Robotics and chief architect for the OB7, recently spoke with Robotics Business Review about the innovative cobot, safety considerations, and the need to educate the market.

Understanding ease of use

“I started in the mid-’80s with robotic cameras for special effects and motion picture work,” Bogart recalled. “We were really working with artists, and what they cared about the most was how the robot moved far more than how accurate it was.”

“Our whole focus on communicating with the robot through the user interface was about how you want the robot to move and what you want it to do without having to program,” he said. “We arrived at that conclusion before we’d ever heard the term cobot.”

“ZBE serves the high-end digital printing and the photo industry. Productive Robotics spun off with mostly the same engineering team,” said Bogart. “Our impetus for getting into robotics was that I don’t think there will be a time in the future when there will be fewer robots than today.”

“We’re nontraditional folks, and we’ve been selling to SMEs [small and midsize enterprises] for a long time,” he said. “We understand the way they think and their infrastructure, which is not like the big auto companies. We need a robot that doesn’t have a team of engineers behind it.”

Seven points of articulation

OB7’s seventh degree of freedom is one more than in many robotic arms. The seventh axis is similar to that of a human’s upper arm between the shoulder and elbow.

“It’s the same motion when you want to arm wrestle, hug someone, or reach around,” Bogart said.

OB7 can reach around, allowing room for people to have access. Source: Productive Robotics

“If you want to use a robot in CNC machine tending, which is a pretty common application, if you have a seventh axis, you can have the robot to reach in from the side,” he explained. “This allows a person to get in and change tools.”

“For people who are doing machine tending, it struck a chord,” he added. “The ones who really get it immediately are the ones who have worked with six-axis machines.”

“What we did with the mass for the seventh axis, we put it at the end of the second axis. J1 does the rotation and J2 are the boom arm,” Bogart said, referring to the cobot’s joints. “J3 is at the base of the robot, so the OB7 doesn’t have to carry its weight.”

OB7 selling points

“The No. 1 thing that customers like the most is how easy our robot is to teach; there’s no programming language involved,” said Bogart. “Most other cobots are easy to program — only if you’re a programmer.”

“The price point is also a big deal,” he said. “We achieve that with a new kind of gearing system that we developed in-house, which that we can produce for great deal less money than the traditional harmonic drives.”

OB7’s user interface includes both a tablet and motion guidance for pick-and-place applications.

“The human operator can grab the end of the robot, drags it over to the component to be picked, and pushes a button to close the gripper or turn on the suction cup,” Bogart said. “The person then moves the robot to where the part needs to be placed, pushes the button to release it, and that’s it.”

“Our software figures out everything in between — the approach points, the timing, path, movement, and speed,” he said.

Productive Robotics’ General Equipment Interface (GEI) is not a teach pendant, but a commercial tablet with added electronics, he said. Jobs are represented as tiles.

“For example, for tending a CNC machine, you teach the robot once how to open a door, teach it, and push the “Go” button,” he said. “Then you drag in the tile to open the door.”

Grippers and security

OB7 has a payload of 5kg (11 lb.), has a reach of 1m (3 ft.), and 0.1mm (0.03 in.) repeatable accuracy, according to Productive Robotics.

“We manufacture our own parallel gripper that’s force- and speed-controlled,” Bogart said. “We have some special end-of-arm tooling in development.”

“We also sell the Robotiq line and use an ISO-standard end-of-arm tool plate with same electrical connections as what Universal Robots uses,” he said. “That’s the largest ecosystem of finished end-of-arm tooling.”

While recent studies have found that several robots were vulnerable to hacking, OB7’s software is secured with a proprietary protocol.

“Unlike standard Linux, we have one open port, which is connected to a Web analytics package,” Bogart said. “It’s a portal for our customers to collect production and error information. Plus, for inspection, a camera that’s built into the robot can automatically upload pictures to an analytics platform.”

“They’re backed up to the cloud, and a customer’s ERP [enterprise resource planning] systems can track jobs, parts, operators, and utilization,” he said. “It’s in beta testing right now because we concocted a list of all the data to be collected. Right now, in the hands of four different robot users around the country for feedback.”

Independent development

The OB7 has been shipping this year, and Productive Robotics’ sales have been growing at 50% per month for the past few months.

“We were also doing integration with customers. Prior to this year, we’ve had a couple dozen robots running in our factory and in sister company ZBE,” Bogart said. “In our test facility, we just load them up until they break. The goal is to break them. It’s bittersweet, but we’ve broken a few at workloads that were substantially heavier than they will ever see in the real world.”

The company is self-funded, and the lack of venture capitalists “affords us some flexibility,” Bogart said. “There’s a tendency to getting the product perfect first and selling second.”

The OB7 cobot is commonly used in machine tending. Source: Productive Robotics

Multitasking a ‘nice to have’

For most cobot users, the ability for robots to multitask is seems like a good idea, but most aren’t ready for that yet, Bogart said.

“Customers say they’re there, but they’re not as far along,” he said. “Most come back needing another robot.”

“Our focus with OB7 is to have as full a solution as possible,” Bogart noted. “We have self-contained production assembly cell with an optional stand and an assembly table. It’s equipped with a scanner so you can run it at higher speeds or slow the robot to collaborative speeds.”

The stand can be rolled from one machine to another, but that causes another set of challenges.

“It’s pretty well known among seasoned robot users and integrators that whenever you move a robot, you have to touch up all the moves,” said Bogart. “We use standard QR code plaques on machines for alignment. For example, you can put them next to a door handle or on a panel next to the start button.”

If a robot is doing the same job, it doesn’t need another risk assessment, but one would be needed for new locations, he acknowledged.

“ISO 10218 is crystal clear at 250 mm/sec. in collaborative mode,” Bogart said. “You can see lots of YouTube videos of robots running a heck of a lot faster than that speed with no protection around them.”

“If people are doing that, then they’re probably not doing a lot in the way of risk assessments,” he said. “We’re borderline militant about insisting that our customers do them. They’re important, and [risks are] not always obvious.”

“We’ve had fewer in packaging than anticipated, but we have strong distribution network in plastic molding and hot stamping of parts,” he said. “There’s a big hole right now in education.”

“Our application engineers have received some complicated requests,” said Bogart. “For instance, for a medical device manufacturer, the robot is doing a substantial bit of shaping and assembling a component.”

“We’ve got one hanging off the side of a wall,” he said. “There’s an OB7 that’s greasing up springs and one that’s putting together water-aeration filters for public fountains.”

Eugene Demaitre is senior editor for Robotics Business Review. Prior to joining EH Publishing in the Boston area, he worked as an editor at BNA, Computerworld, and TechTarget. Demaitre has a master's degree in international affairs from the George Washington University.